Channel reconfiguration in a communications network based on measurements by wireless devices and network node

ABSTRACT

Mechanisms are provided for channel reconfiguration in a communications network where shared spectrum from a primary incumbent is used. A method is performed by a network node, which comprises obtaining RSSI measurements on the current channel from wireless devices. The wireless devices are served by the network node at a current channel in a current frequency interval within a frequency band. When the RSSI measurements trigger a need for the network node to perform channel reconfiguration, the network node selects a new channel based on RSSI measurements that it itself performs. The method comprises selecting a new channel in a new or the same frequency interval, in a new or the same frequency band, for serving the wireless devices based on RSSI measurements performed by the network node, and channel reconfiguration for the wireless devices is performed.

TECHNICAL FIELD

Embodiments presented herein relate to a method, a network node, acomputer program, and a computer program product for channelreconfiguration in a communications network.

BACKGROUND

In communications networks, there may be a challenge to obtain goodperformance and capacity for a given communications protocol, itsparameters and the physical environment in which the communicationsnetwork is deployed.

Current practices for wireless mobile communications have focused ondesigning systems for wide area coverage in frequency bands that roughlyextend between 400 MHz to 100 GHz, although there is no physicallimitation that strictly limits such systems to that range. The trafficgrowth on mobile networks has grown to the point where the mobileindustry is consistently starved for spectrum.

Every generation of wireless technology has improved the metricsunderlying spectrum efficiency, typically measured as area efficiencyand denominated in the ratio data rate supported per unit bandwidth percell ((b/s)/Hz/cell).

A memorandum has resulted in regulations from the Federal CommunicationsCommission (FCC) relating to the so-called Citizen's Broadband RadioService (CBRS) defined for the 3550-3700 MHz band. The CBRS definesthree tiers of sharing, with higher tiers providing higher priority ofaccess to spectrum than the lower ones. In general, multiple tiers ofusers can be defined, although three tiers are a pragmatic choice. Theassignment of channels to different tiers and related configurations areperformed by a geolocation database and policy management system knownas the Spectrum Access System (SAS). In the CBRS, naval radar inlittoral waters, and commercial Fixed Satellite Service (FSS) composethe incumbents. The second tier consists of Priority Access Licenses(PALs), and the third tier comprises opportunistic users known asgeneral authorized access (GAA) users. Incumbent radar activity in theCBRS is dynamic, while FSS (space-to-earth) is static. The SAS ischarged with protecting incumbents, and PALs. In addition, the SASauthorizes the authorization of spectrum to GAA users.

FIG. 1 schematically illustrates a part of a communications network. Inmore detail, FIG. 1 schematically illustrates elements of an example SASfunctional architecture. In some aspects the SAS functional architectureis part of a core network 120. A first SAS (denoted SAS 1) isoperatively connected to FCC databases, another SAS (denoted SAS 2), anEnvironmental Sensing Capability (ESC), an Informing Incumbent function,a Domain Proxy and a Citizens Broadband Radio Service Device (CBSD)(denoted CBSD 4). The Domain Proxy is in turn operatively connected(optionally via an Element Management System (EMS)) with CBSDs (denotedCBSD 1, CBSD 2, CBSD 3), and an optional CBSD sensing function.

Accessing spectrum around 3.5 GHz (the so-called CBRS band) is performedfollowing standards defined in WinnForum. A CBSD will first registerwith the SAS and provide its location information among otherregistration parameters, and then it will ask the SAS to grant access ina certain channel. Before granting access, the SAS will use informationfrom the ESC network to detect incumbent activity in the area where CBSDoperates. The SAS will also use measurement reports from the other CBSDsin the same area to determine the level of interference in a certainchannel as well as if the channel needs to be protected due to PAL useractivity. A coexistence management (CXM) function or the Domain Proxyhas the possibility to select which channel the CBSD is to use, and theSAS has the responsibility to ensure interference protection accordingto the rules set out in FCC part 96. In relation to FIG. 1 the CXMfunction could be collocated with the Domain Proxy, with a DomainManager, or with any of the SASs, or with another entity, or be providedas a separate entity; the CXM could generally be regarded as a separatelogical entity that manages co-existence between GAA devices operatingin Long Term Evolution Time Division Duplex (LTE-TDD) mode.

However, there is still a need for achieving improved spectralefficiency in communications networks.

SUMMARY

An object of embodiments herein is to provide efficient channelselection in a communications network.

According to a first aspect there is presented a method for channelreconfiguration in a communications network. The method is performed bya network node. The method comprises obtaining RSSI measurements fromwireless devices. The wireless devices are served by the network node ata current channel in a current frequency interval within a frequencyband. The RSSI measurements trigger a need for the network node toperform channel reconfiguration. The method comprises selecting a newchannel in a new or the same frequency interval, in a new or the samefrequency band, for serving the wireless devices based on RSSImeasurements performed by the network node, thereby performing thechannel reconfiguration.

According to a second aspect there is presented a network node forchannel reconfiguration in a communications network. The network nodecomprises processing circuitry. The processing circuitry is configuredto cause the network node to obtain RSSI measurements from wirelessdevices. The wireless devices are served by the network node at acurrent channel in a current frequency interval within a frequency band.The RSSI measurements trigger a need for the network node to performchannel reconfiguration. The processing circuitry is configured to causethe network node to select a new channel in a new or the same frequencyinterval, in a new or the same frequency band, for serving the wirelessdevices based on RSSI measurements performed by the network node,thereby performing the channel reconfiguration.

According to a third aspect there is presented a network node forchannel reconfiguration in a communications network. The network nodecomprises processing circuitry and a storage medium. The storage mediumstores instructions that, when executed by the processing circuitry,cause the network node to perform operations, or steps. The operations,or steps, cause the network node to obtain RSSI measurements fromwireless devices. The wireless devices are served by the network node ata current channel in a current frequency interval within a frequencyband. The RSSI measurements trigger a need for the network node toperform channel reconfiguration. The operations, or steps, cause thenetwork node to select a new channel in a new or the same frequencyinterval, in a new or the same frequency band, for serving the wirelessdevices based on RSSI measurements performed by the network node,thereby performing the channel reconfiguration.

According to a fourth aspect there is presented a network node forchannel reconfiguration in a communications network. The network nodecomprises an obtain module configured to obtain RSSI measurements fromwireless devices. The wireless devices are served by the network node ata current channel in a current frequency interval within a frequencyband. The RSSI measurements trigger a need for the network node toperform channel reconfiguration. The network node comprises a selectmodule configured to select a new channel in a new or the same frequencyinterval, in a new or the same frequency band, for serving the wirelessdevices based on RSSI measurements performed by the network node,thereby performing the channel reconfiguration.

According to a fifth aspect there is presented a computer program forchannel reconfiguration in a communications network, the computerprogram comprising computer program code which, when run on a networknode, causes the network node to perform a method according to the firstaspect.

According to a sixth aspect there is presented a computer programproduct comprising a computer program according to the fifth aspect anda computer readable storage medium on which the computer program isstored. The computer readable storage medium could be a non-transitorycomputer readable storage medium.

Advantageously this method, these network nodes, this computer program,and this computer program product provide efficient channel selection inthe communications network.

Advantageously this method, these network nodes, this computer program,and this computer program product improve the reliability of frequencyselection in a network node with consideration of both uplink anddownlink interference level, without requiring a change of anyinterfaces as standardized by the 3rd Generation Partnership Project(3GPP).

It is to be noted that any feature of the first, second, third, fourth,fifth and sixth aspects may be applied to any other aspect, whereverappropriate. Other objectives, features and advantages of the enclosedembodiments will be apparent from the following detailed disclosure,from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted accordingto their ordinary meaning in the technical field, unless explicitlydefined otherwise herein. All references to “a/an/the element,apparatus, component, means, module, step, etc.” are to be interpretedopenly as referring to at least one instance of the element, apparatus,component, means, module, step, etc., unless explicitly statedotherwise. The steps of any method disclosed herein do not have to beperformed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating a part of a communicationsnetwork;

FIG. 2 is a schematic diagram illustrating a communications networkaccording to embodiments;

FIGS. 3, 5, and 6 are flowcharts of methods according to embodiments;

FIG. 4 schematically illustrates a frequency band according to anembodiment;

FIG. 7 is a schematic diagram showing functional units of a network nodeaccording to an embodiment;

FIG. 8 is a schematic diagram showing functional modules of a networknode according to an embodiment; and

FIG. 9 shows one example of a computer program product comprisingcomputer readable storage medium according to an embodiment.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter withreference to the accompanying drawings, in which certain embodiments ofthe inventive concept are shown. This inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided by way of example so that this disclosure will be thorough andcomplete, and will fully convey the scope of the inventive concept tothose skilled in the art. Like numbers refer to like elements throughoutthe description. Any step or feature illustrated by dashed lines shouldbe regarded as optional.

FIG. 2 is a schematic diagram illustrating a radio communicationsnetwork 100 where embodiments presented herein can be applied. Thecommunications network 100 comprises a radio access network 110, a corenetwork 120, and a service network 130. The radio access network 110comprises a network node 200 that is configured to, via a transmissionand reception point (TRP) 205, communicate with wireless devices 300 a,300 b. The wireless devices 300 a, 300 b are thereby enabled to accessservices and exchange data with the service network 130. The corenetwork 120 could comprise the elements of the SAS functionalarchitecture given in FIG. 1.

Examples of network nodes 200 are CBSDs, radio base stations, basetransceiver stations, Node Bs, evolved Node Bs, gigabit Node Bs, accesspoints, and access nodes. Examples of wireless devices 300 a, 300 b aremobile stations, mobile phones, handsets, wireless local loop phones,user equipment (UE), smartphones, laptop computers, tablet computers,network equipped sensors, network equipped vehicles, and so-calledInternet of Things devices. In some aspects at least one of the wirelessdevices 300 a, 300 b is a wireless device with high UE category, forexample category 6 or higher.

The embodiments disclosed herein relate to mechanisms for channelreconfiguration in a communications network 100. In order to obtain suchmechanisms there is provided a network node 200, a method performed bythe network node 200, a computer program product comprising code, forexample in the form of a computer program, that when run on a networknode 200, causes the network node 200 to perform the method.

The inventors of the enclosed embodiments have realized that in anoperating communications network, the network node and wireless devicesserved by the network node have different interfering sources. Thereliability of the channel selection might therefore be improved ifconsidering received signal strength indicator (RSSI) measurementsperformed both by the served wireless devices and the network node.However, it is still unknown how to use RSSI measurements from wirelessdevices and how to combine them with RSSI measurements from the networknode during channel selection.

The inventors of the enclosed embodiments have further realized that inorder to provide reliable services in the communications network, theselected channel assignment should be continuously monitored in orderfor the network node to detect new interference sources that couldappear when e.g. new network nodes are deployed in the surroundings orif locations of the wireless devices served by the network node changesignificantly during the day or weekend. As locations of wirelessdevices and radio propagation characteristics are difficult to predict,using measurements from the wireless devices might me more accurate thanmeasurements of the network node.

FIGS. 3 and 5 are flowcharts illustrating embodiments of methods forchannel reconfiguration in a communications network 100. The methods areperformed by the network node 200. The methods are advantageouslyprovided as computer programs 920.

Reference is now made to FIG. 3 illustrating a method for channelreconfiguration in a communications network 100 as performed by thenetwork node 200 according to an embodiment.

The network node 200 will use RSSI measurements reported periodicallyfrom served wireless devices 300 a, 300 b to trim and trigger channelreconfiguration. The network node 200 will collect RSSI measurements forall served wireless devices 300 a, 300 b over one or several measurementperiods. Hence, the network node 200 is configured to perform step S102:

S102: The network node 200 obtains RSSI measurements from wirelessdevices 300 a, 300 b. The wireless devices 300 a, 300 b are served bythe network node 200 at a current channel. The current channel islocated in a current frequency interval. The current frequency intervalis, in turn, located within a frequency band. The RSSI measurementstrigger a need for the network node 200 to perform channelreconfiguration.

That is, the RSSI measurements as performed by the wireless devices 300a, 300 b trigger the network node 200 to perform channelreconfiguration. During the channel reconfiguration the network node 200utilizes its own RSSI measurements. Hence, the network node 200 isconfigured to perform step S104:

S104: The network node 200 selects a new channel in a new or the samefrequency interval, in a new or the same frequency band. The new channelis selected for serving the wireless devices 300 a, 300 b. The selectionof the new channel is based on RSSI measurements performed by thenetwork node 200. The network node 200 thereby performs the channelreconfiguration.

Embodiments relating to further details of channel reconfiguration in acommunications network 100 as performed by the network node 200 will nowbe disclosed.

Assume that the current channel is located at a current frequency.According to an embodiment the RSSI measurements from the wirelessdevices 300 a, 300 b comprise RSSI measurements performed at the currentfrequency as well as at at least one further frequency. The at least onefurther frequency is located at a frequency offset to the currentfrequency (or even to the current frequency interval). The at least onefurther frequency could therefore be denoted a neighbour frequency. Asan example, the frequency offset could be selected to have a value inthe range [2.5+BW, 5+BW] MHz, where BW is the occupied bandwidth of thecurrent frequency interval.

As an example, after the wireless devices 300 a, 300 b successfully campon the network node 200 (or on cell in which the network node 200provides network access), the network node 200 could instruct thewireless devices 300 a, 300 b to perform RSSI measurements on one ormore neighbor frequencies for inter-frequency RSSI measurement. Suchinstructions could be provided from the network node 200 to the wirelessdevices 300 a, 300 b in an information element denoted MeasConfig.

That is, the at least one further frequency is located outside thecurrent frequency interval. The RSSI measurements thereby representmeasurements performed both inside the current frequency interval andoutside the current frequency interval. It could thereby be possible forthe network node 200 to check how many wireless devices 300 a, 300 bthat have strong interference from one or more neighbor frequencies.

The channel reconfiguration could then be triggered when the RSSImeasurements performed at the at least one further frequency indicatehigh interference.

According to an embodiment the channel reconfiguration is triggered whena difference between the RSSI measurements performed at the currentfrequency and the RSSI measurements performed at the at least onefurther frequency is smaller than a threshold value for at least aportion of the wireless devices 300 a, 300 b. That is, when the networknode 200 receives the RSSI measurements from the wireless devices 300 a,300 b, the network node 200 might check how many wireless devices 300 a,300 b have strong interference at the at least one further frequency.Denote by RSSI(fc) the RSSI measurement at the current frequency and byRSSI(f1) the RSSI measurement at one of the at least one furtherfrequency. Then, if RSSI(fc)−RSSI(f1)<Threshold1, there is stronginterference from frequency f1, and so on for all remaining neighbourfrequencies (i.e., for all remaining ones of the at least one furtherfrequency). In other words, in an ideal situation the RSSI measurementsperformed by the wireless devices 300 a, 300 b within the currentfrequency interval (such as at at the current frequency) are much higherthan the RSSI measurements performed by the wireless devices 300 a, 300b outside the current frequency interval (such as at the one or moreneighbour frequencies). If this is not the case it could be beneficialto re-locate the current channel to a new channel.

In some aspects the channel reconfiguration is triggered when there aremore than a first certain portion (for example, 20%) of all servedwireless devices 300 a, 300 b or some second certain portion (forexample, 10%) of wireless devices 300 a with high UE category that havestrong interference from one or more neighbor frequencies. That is,according to an embodiment the channel reconfiguration is triggered whenthe RSSI measurements from at least a portion (i.e., the above mentionedfirst certain portion) of all wireless devices 300 a, 300 b from whichRSSI measurements are received indicate high interference. And,according to an embodiment the channel reconfiguration is triggered whenthe RSSI measurements from at least a portion (i.e., the above mentionedsecond certain portion) of wireless devices 300 a with high UE categoryfrom which RSSI measurements are received indicate high interference.

In general terms, any channel as mentioned herein is located at acertain frequency. The term channel as used herein could therefore,unless otherwise stated, be denoted as a frequency channel.

In particular, according to an embodiment the current channel is locatedat a current frequency centered in the current frequency interval andthe new channel is located at a new frequency centered in the newfrequency interval. The new frequency interval could be selected suchthat the new frequency is located outside the current frequencyinterval. In other aspects the new channel is located in the samefrequency interval as the current channel. This could be the case wherethe RSSI measurements of the network node 200 indicate that the currentfrequency interval is still the best choice for placing the new channel,although the RSSI measurements from the wireless devices 300 a, 300 btriggers the network node 200 to perform channel reconfiguration.

In further aspects, the new frequency (i.e., the frequency of the newchannel) could be selected to have a certain frequency separation to theone or more neighbour frequencies with strong interference detected bythe wireless devices 300 a, 300 b. That is, according to an embodimentthe new frequency interval is selected to be distanced to at least oneof the at least one further frequency as well as to the currentfrequency (or even to the current frequency interval). Thereby, if thereare wireless devices 300 a, 300 b reporting high RSSI measurements fromone or more neighbor frequencies, the network node 200 a willreconfigure the channel based on RSSI measurements made by the networknode 200 itself and make sure that the new channel has a safe distanceto any neighbouring frequencies with high RSSI as reported by thewireless devices 300 a, 300 b.

Intermediate reference is now made to FIG. 4. FIG. 4 schematicallyillustrates a frequency band 400 along a frequency axis. Within thefrequency band is located a current frequency interval and a newfrequency interval. A current channel is located at a current frequency(denoted fc_(current)) within the current frequency interval and a newchannel is located at a new frequency (denoted fc_(new)) within the newfrequency interval. Two neighbouring frequencies located at an offset tothe current frequency interval are denoted f1 and f2. According to theillustrative example of FIG. 4, the new frequency interval is locatedsuch that it does not contain any of the neighbouring frequencies f1,f2.

In general terms, as disclosed above, the channel reselection is mainlybased on RSSI measurement performed by the network node 200. Accordingto an embodiment the RSSI measurements performed by the network node 200are performed prior to being triggered to perform channelreconfiguration. Such RSSI measurements represent historical RSSImeasurements. According to another embodiment the RSSI measurementsperformed by the network node 200 are performed in response to beingtriggered to perform channel reconfiguration. Such RSSI measurementsrepresent new RSSI measurements. In this respect, if historical RSSImeasurements as performed by network node 200 are not available, thenetwork node 200 thus needs to schedule RSSI measurement within a properfrequency range. When there are historical RSSI measurements available,the network node 200 could select the new channel according to thehistorical RSSI measurements, thus avoiding the scheduling of new RSSImeasurements.

Reference is now made to FIG. 5 illustrating methods for channelreconfiguration in a communications network 100 as performed by thenetwork node 200 according to further embodiments. It is assumed thatsteps S102 and S104 are performed as described above with reference toFIG. 3 and a thus repeated description thereof is therefore omitted.

In some aspects the network node 200 needs permission from the SAS touse the new channel. The network node 200 might therefore need torequest access from the SAS. Hence, according to an embodiment thenetwork node 200 is configured to perform step S106:

S106: The network node 200 requests, from the SAS, access to use the newchannel.

If a grant of the access is not received from the SAS the network node200 could select another new channel, wherein this another new channelis selected in the same way as the originally selected new channel, butwith the condition, or side constraint, that this another new channelmust be different from the originally selected new channel.

Further, the network node 200 might need to inform the wireless devices300 a, 300 b of the new channel so that the wireless devices 300 a, 300c can shift to the new channel in order to be served by the network node200. Hence, according to an embodiment the network node 200 isconfigured to perform step S108:

S108: The network node 200 notifies the wireless devices 300 a, 300 b ofthe new channel in order to serve the wireless devices 300 a, 300 b inthe new channel.

There could be different types, or examples, of frequency bands withinwhich the current frequency interval and the new frequency interval arelocated. In some aspects the frequency band is an unlicensed frequencyband. Hence, according to an embodiment the current frequency intervaland the new frequency interval are part of an unlicensed frequency band.In some aspects the frequency band is the so-called 3550-3700 MHzfrequency band. Hence, according to an embodiment the current frequencyinterval and the new frequency interval are selected to be locatedwithin the frequency band extending from 3550 MHz and 3700 MHz. In someaspects the frequency band is a CBRS frequency band. Hence, according toan embodiment the current frequency interval and the new frequencyinterval are selected to be located within a CBRS frequency band.According to some aspects, one of the (current) frequency band and thenew frequency band is a Citizens Broadband Radio Service, CBRS,frequency band and the other of the (current) frequency band and the newfrequency band is, for example, a third generation partnership project,3GPP, frequency band.

One particular embodiment of channel reconfiguration in a communicationsnetwork 100 as performed by the network node 200 will now be disclosedwith reference to the flowchart of FIG. 6 (where NN is short for thenetwork nodes 200 and WD is short for wireless device 300 a, 300 b).

S201: The network node 200 configures wireless device 300 a, 300 b thatsuccessfully camp on the network node 200 to perform RSSI measurementsat neighbouring frequencies f1, f2.

S202: The wireless devices 300 a, 300 b perform RSSI measurements at thefrequency fc_(current) of the current channel neighbouring frequenciesf1, f2 and report these RSSI measurements periodically to the networknode 200, which thus obtains the RSSI measurements.

S203: The network node 200 checks how many of the wireless devices 300a, 300 b have strong interference from one or more of the neighborfrequencies f1, f2 according to the RSSI measurements.

S204: The network node 200 checks if more than a certain portion of thewireless devices 300 a, 300 b have strong interference from one or moreof the neighbor frequencies f1, f2 according to the RSSI measurements.If no, step S202 is entered again. If yes, step S205 is entered.

S205: The RSSI measurements as performed by the wireless devices 300 a,300 b trigger channel reconfiguration to be made by the network node200.

S206: The network node 200 selects a new channel based on RSSImeasurements performed by the network node 200 in accordance with whathas been disclosed above. These RSSI measurements are either historicalRSSI measurements or new RSSI measurements.

S207: The network node 200 requests, from the SAS, access to use the newchannel. If a grant of the access is not received, step S206 is enteredagain for the network node 200 to select another new channel. If a grantof the access is received, step S208 is entered.

S208: The network node 200 notifies the wireless devices 300 a, 300 b ofthe new channel and serves the wireless devices 300 a, 300 b in the newchannel.

FIG. 7 schematically illustrates, in terms of a number of functionalunits, the components of a network node 200 according to an embodiment.Processing circuitry 210 is provided using any combination of one ormore of a suitable central processing unit (CPU), multiprocessor,microcontroller, digital signal processor (DSP), etc., capable ofexecuting software instructions stored in a computer program product 910(as in FIG. 9), e.g. in the form of a storage medium 230. The processingcircuitry 210 may further be provided as at least one applicationspecific integrated circuit (ASIC), or field programmable gate array(FPGA).

Particularly, the processing circuitry 210 is configured to cause thenetwork node 200 to perform a set of operations, or steps, S102-S108, asdisclosed above. For example, the storage medium 230 may store the setof operations, and the processing circuitry 210 may be configured toretrieve the set of operations from the storage medium 230 to cause thenetwork node 200 to perform the set of operations. The set of operationsmay be provided as a set of executable instructions.

Thus the processing circuitry 210 is thereby arranged to execute methodsas herein disclosed. The storage medium 230 may also comprise persistentstorage, which, for example, can be any single one or combination ofmagnetic memory, optical memory, solid state memory or even remotelymounted memory. The network node 200 may further comprise acommunications interface 220 at least configured for communications withother entities, nodes, and devices, such as the wireless devices 300 a,300 b and the spectrum access system, in the communications network 100.As such the communications interface 220 may comprise one or moretransmitters and receivers, comprising analogue and digital components.The processing circuitry 210 controls the general operation of thenetwork node 200 e.g. by sending data and control signals to thecommunications interface 220 and the storage medium 230, by receivingdata and reports from the communications interface 220, and byretrieving data and instructions from the storage medium 230. Othercomponents, as well as the related functionality, of the network node200 are omitted in order not to obscure the concepts presented herein.

FIG. 8 schematically illustrates, in terms of a number of functionalmodules, the components of a network node 200 according to anembodiment. The network node 200 of FIG. 8 comprises a number offunctional modules; an obtain module 210 a configured to perform stepS102 and a select module 210 b configured to perform step S104. Thenetwork node 200 of FIG. 8 may further comprise a number of optionalfunctional modules, such as any of a request module 210C configured toperform step S106, and a notify module 210 d configured to perform stepS108. In general terms, each functional module 210 a-210 d may in oneembodiment be implemented only in hardware and in another embodimentwith the help of software, i.e., the latter embodiment having computerprogram instructions stored on the storage medium 230 which when run onthe processing circuitry 210 makes the network node 200 perform thecorresponding steps mentioned above in conjunction with FIG. 8. Itshould also be mentioned that even though the modules correspond toparts of a computer program, they do not need to be separate modulestherein, but the way in which they are implemented in software isdependent on the programming language used. Preferably, one or more orall functional modules 210 a-210 d may be implemented by the processingcircuitry 210, possibly in cooperation with the communications interface220 and/or the storage medium 230. The processing circuitry 210 may thusbe configured to from the storage medium 230 fetch instructions asprovided by a functional module 210 a-210 d and to execute theseinstructions, thereby performing any steps as disclosed herein.

The network node 200 may be provided as a standalone device or as a partof at least one further device. As disclosed above, the network node 200could be a CBSD. For example, the network node 200 may be provided in anode of the radio access network or in a node of the core network.Alternatively, functionality of the network node 200 may be distributedbetween at least two devices, or nodes. These at least two nodes, ordevices, may either be part of the same network part (such as the radioaccess network or the core network) or may be spread between at leasttwo such network parts.

Thus, a first portion of the instructions performed by the network node200 may be executed in a first device, and a second portion of the ofthe instructions performed by the network node 200 may be executed in asecond device; the herein disclosed embodiments are not limited to anyparticular number of devices on which the instructions performed by thenetwork node 200 may be executed. Hence, the methods according to theherein disclosed embodiments are suitable to be performed by a networknode 200 residing in a cloud computational environment. Therefore,although a single processing circuitry 210 is illustrated in FIG. 7 theprocessing circuitry 210 may be distributed among a plurality ofdevices, or nodes. The same applies to the functional modules 210 a-210d of FIG. 8 and the computer program 920 of FIG. 9 (see below).

FIG. 9 shows one example of a computer program product 910 comprisingcomputer readable storage medium 930. On this computer readable storagemedium 930, a computer program 920 can be stored, which computer program920 can cause the processing circuitry 210 and thereto operativelycoupled entities and devices, such as the communications interface 220and the storage medium 230, to execute methods according to embodimentsdescribed herein. The computer program 920 and/or computer programproduct 910 may thus provide means for performing any steps as hereindisclosed.

In the example of FIG. 9, the computer program product 910 isillustrated as an optical disc, such as a compact disc (CD) or a digitalversatile disc (DVD) or a Blu-Ray disc. The computer program product 910could also be embodied as a memory, such as a random access memory(RAM), a read-only memory (ROM), an erasable programmable read-onlymemory (EPROM), or an electrically erasable programmable read-onlymemory (EEPROM) and more particularly as a non-volatile storage mediumof a device in an external memory such as a Universal Serial Bus (USB)memory or a Flash memory, such as a compact Flash memory. Thus, whilethe computer program 920 is here schematically shown as a track on thedepicted optical disk, the computer program 920 can be stored in any waywhich is suitable for the computer program product 910.

The inventive concept has mainly been described above with reference toa few embodiments. However, as is readily appreciated by a personskilled in the art, other embodiments than the ones disclosed above areequally possible within the scope of the inventive concept, as definedby the appended patent claims.

The invention claimed is:
 1. A method for channel reconfiguration in acommunications network, the method being performed by a network node,the method comprising: obtaining received signal strength indicator(RSSI) measurements from wireless devices, the wireless devices beingserved by the network node at a current channel in a current frequencyinterval within a frequency band, the RSSI measurements triggering aneed for the network node to perform channel reconfiguration; andselecting a new channel in a new or the same frequency interval, in anew or the same frequency band, for serving the wireless devices by thenetwork node based on RSSI measurements performed by the network node,thereby performing the channel reconfiguration.
 2. The method accordingto claim 1, wherein the current channel is located at a currentfrequency, wherein the RSSI measurements from the wireless devicescomprise RSSI measurements performed at the current frequency as well asat at least one further frequency, the at least one further frequencybeing located at a frequency offset to the current frequency.
 3. Themethod according to claim 2, wherein the channel reconfiguration istriggered when the RSSI measurements performed at the at least onefurther frequency indicate high interference.
 4. The method according toclaim 2, wherein the channel reconfiguration is triggered when adifference between the RSSI measurements performed at the currentfrequency and the RSSI measurements performed at the at least onefurther frequency is smaller than a threshold value for at least aportion of the wireless devices.
 5. The method according to claim 2,wherein the new frequency interval is selected to be distanced to atleast one of the at least one further frequency, as well as to thecurrent frequency.
 6. The method according to claim 1, wherein thechannel reconfiguration is triggered when the RSSI measurements from atleast a portion of all wireless devices from which RSSI measurements arereceived indicate high interference.
 7. The method according to claim 1,wherein the channel reconfiguration is triggered when the RSSImeasurements from at least a portion of wireless devices with a high UEcategory, from which RSSI measurements are received indicate highinterference.
 8. The method according to claim 1, wherein the RSSImeasurements performed by the network node are performed prior to beingtriggered to perform channel reconfiguration.
 9. The method according toclaim 1, wherein the RSSI measurements performed by the network node areperformed in response to being triggered to perform channelreconfiguration.
 10. The method according to claim 1, furthercomprising: requesting, from a spectrum access system (SAS) access touse the new channel.
 11. The method according to claim 1, furthercomprising: notifying the wireless devices of the new channel, in orderto serve the wireless devices in the new channel.
 12. The methodaccording to claim 1, wherein the current channel is located at acurrent frequency in the current frequency interval and the new channelis located at a new frequency in the new frequency interval.
 13. Themethod according to claim 12, wherein the new frequency interval isselected such that the new frequency is located outside the currentfrequency interval.
 14. The method according to claim 1, wherein thecurrent frequency interval and the new frequency interval are part of anunlicensed frequency band.
 15. The method according to claim 1, whereinthe current frequency interval and the new frequency interval areselected to be located within the frequency band extending from 3550 MHzand 3700 MHz.
 16. The method according to claim 1, wherein the currentfrequency interval and the new frequency interval are selected to belocated within a Citizens Broadband Radio Service (CBRS) frequency band.17. The method according to claim 1, wherein one of the frequency bandand the new frequency band is a Citizens Broadband Radio Service (CBRS)frequency band and the other of the frequency band and the new frequencyband is a third generation partnership project (3GPP) frequency band.18. The method according to claim 1, wherein the network node is aCitizens Broadband Radio Service Device (CBSD).
 19. A network node forchannel reconfiguration in a communications network, the network nodecomprising processing circuitry, the processing circuitry beingconfigured to cause the network node to: obtain received signal strengthindicator (RSSI) measurements from wireless devices, the wirelessdevices being served by the network node at a current channel in acurrent frequency interval within a frequency band, the RSSImeasurements triggering a need for the network node to perform channelreconfiguration; and select a new channel in a new or the same frequencyinterval, in a new or the same frequency band, for serving the wirelessdevices by the network node based on RSSI measurements performed by thenetwork node, thereby performing the channel reconfiguration.
 20. Anetwork node for channel reconfiguration in a communications network,the network node comprising: processing circuitry; and a storage mediumstoring instructions that, when executed by the processing circuitry,cause the network node to: obtain received signal strength indicator(RSSI) measurements from wireless devices, the wireless devices beingserved by the network node at a current channel in a current frequencyinterval within a frequency band, the RSSI measurements triggering aneed for the network node to perform channel reconfiguration; and selecta new channel in a new or the same frequency interval, in a new or thesame frequency band, for serving the wireless devices by the networknode based on RSSI measurements performed by the network node, therebyperforming the channel reconfiguration.
 21. The network node accordingto claim 20, wherein the network node is a Citizens Broadband RadioService Device (CBSD).
 22. A network node for channel reconfiguration ina communications network, the network node comprising: an obtain moduleconfigured to obtain received signal strength indicator (RSSI)measurements from wireless devices, the wireless devices being served bythe network node at a current channel in a current frequency intervalwithin a frequency band, the RSSI measurements triggering a need for thenetwork node to perform channel reconfiguration; and a select moduleconfigured to select a new channel in a new or the same frequencyinterval, in a new or the same frequency band, for serving the wirelessdevices by the network node based on RSSI measurements performed by thenetwork node, thereby performing the channel reconfiguration.